burning smell in mark III

[johnnyfancy]

so i was just playing my black dot coli at tv volumes and noticed a burning smell, then saw a litle bit of smoke coming from behind the eq. i turned it off and unplugged it. it's never had any problems before. any ideas? thanks i hope it's not fried, i sure do love this thing

 

[DaveP]

I had that happen on my Mark II, turns out it was the on/off switch that was the issue. Turned it on and then the dreaded operational smoke.

 

[johnnyfancy]

interesting, when i turned it on yesterday, i thought something seemed wierd,but it sounded and played fine. is it just a matter of switching out the switch? i'm not turning it back on for awhile

 

[johnnyfancy]

so i just plugged it back in. the power was off, and yet the light and fan were on. hit the stangyby switch and it fired up. guessing it's the switch. does anyone know of any good amp techcs in the northern va washington dc area?

 

[SonicProvocateur]

Mine Mark III did the "weird" sound thing shortly before it popped a tube, smoked, and died. Turned out it was a screen grid resistor leaking before it burned out completely, however it could be alot of things from a solder burning out to a cap, etc. I would suggest not running it anymore before either checking it yourself, or having it professionally looked over. This will preserve the life of your Mesa.

 

[johnnyfancy]

taking it to a tech tomorrow. i opened it up today and can't see anything wrong :? what do i know though i did notice kdrg17 written in sharpie on the side. what is this?

 

[zebpedersen]

The chassis codes are written on the side of all Mark series chassis and denote the options ordered on that particular amplifier.

KDRG reads Coliseum/Simul-class/Reverb/Graphic EQ, if I'm not mistaken. HRG would be 100W/Reverb/Graphic and SR would be 60W with reverb.

There's a few explanations of the codes around, the basic letters are:

H - 100W
S - 60W
R - Reverb
G - Graphic EQ

And combinations thereof...if I'm incorrect, have a quick Google of it, as far as I remember those codes are the usual ones. Good luck at the amp doctor

(I wasn't aware they did Simul Coliseum amps, thought they were Class A only...anyone?)